Not sure whether I would remain cool in that situation, so part of that valuable time might go off to panic or shock reactions. The more substantial part, though, would probably be devoted to trying to communicate a farewell to my family and friends (and be this by forming a particular knot or scratching a message on my helmet), and some minutes in between to my life, the peculiarities of my situation (is there really no way out?) and the spectacular views I get on the planet (I assume we are orbiting Earth) and “my” space ship, as well as to the question of what celestial object my corpse would eventually collide with, and when.